Dinosaur Hunter

Joe Sertich now works at the Denver Museum of Nature & Science, where he studies how climate change and plate tectonics shaped the evolution of dinosaurs. This past spring, Sertich announced his latest Mesozoic discovery—a “new” carnivorous dinosaur from Madagascar called Dahalokely tokana.

Where do you begin when you’re looking for fossils?You get an idea of what the bones or footprints look like, and then you just hike a lot. In the United States, it can be in extremely remote areas where nobody lives, where there’s no vegetation—and you’re just hiking mud hills. Then you find a bone, or a crumble of bone, and you dig into the hill to see if it’s connected to a bigger chunk of an animal. When the bones continue, it’s a total adrenaline rush. You’re the first person to ever see it. It’s an amazing experience.

You recently announced the discovery of a new dinosaur.I have discovered dozens of new dinosaurs or other extinct animals. There is a misconception that we know everything. Every time we go out to the field we find something new.

What’s the best part of the job?It’s not a glamorous profession. We are living in tents for a good chunk of the year, and the other part of the year we’re writing grants to be able to live in tents. The payoff is making a discovery or showing kids new fossils and seeing their eyes light up.

Was Denver an important piece of dinosaur history?Denver actually sits on the story of the extinction event for the dinosaurs. From just north of Denver all the way down to Colorado Springs, there’s a huge basin that has T. rex and Triceratops at the bottom, then the extinction event in the middle, and then the first two million years of recovery. So this whole area is a dinosaur boneyard. You can literally go into your backyard in some parts of Denver and find dinosaur bones.

What’s your favorite dinosaur?Ceratosaurus. It’s a carnivorous dinosaur that lived alongside Allosaurus in the Jurassic, and it was found here in Colorado. It has these cool horns on its head, armor on its body, and it’s closely related to a lot of the dinosaurs that I dig up in the Southern Hemisphere.

Any interesting stories from the field?I was wading out into the muddy water in Lake Turkana in northern Kenya, an area where I’ve been digging for dinosaurs for many years, when a huge crocodile surfaced feet from where I was standing. It was probably as surprised as I was, but the crocodiles in the lake are known to be man-eaters, so I didn’t wait to find out how hungry it was.

Most kids go through a phase where they love dinosaurs; I just never really grew out of it. In college I started studying geology and biology, and I saw how you could combine them to understand the past. That’s when I fell in love with it.

What areas of dinosaur study do you focus on?

I am trying to understand past ecosystems and how they change. So what was the Rocky Mountain region like between 90 and 66 million years ago? I look at dinosaurs, but also other animals like crocodiles, turtles, birds, fish, and insects. I also work in the Southern Hemisphere, where I study how plate tectonics influenced evolution.

You have a master’s in geology and a Ph.D. in human anatomy. How do these topics inform your work?

The rocks are the story. They tell you what the environment was like and how the dinosaurs, or other extinct animals, became entombed. That’s the geology side of who I am. But understanding the animals themselves—their anatomy, their behavior, their physiology—all of that comes from the anatomical side.

What projects are you working on right now to help put that big picture together?

Here in North America I’m working in Southern Utah’s Grand Staircase-Escalante National Monument. We’re pulling out new dinosaurs and new ecosystems from this part of the world, from 74 million to 80 million years ago.

Anything exciting happening soon at DMNS?

We’re kicking off a big new program focused on making discoveries. We want to unlock the dinosaur story of the Rocky Mountains. We are on the cusp of something really big, and in the next few years, I think Denver will become the center of dinosaur paleontology in the West.